SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'ae8e91649eb92292e6441139f19d116bb5fed57ab9137ae66c6e5b922cb78325' 
  AND token = '433MImGdhLTmsf3gEHUj3kXGYr9gkCSD6+jMtvyhvZw=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00025

JSON explain

{
  "query_block": {
    "select_id": 1,
    "table": {
      "message": "Impossible WHERE noticed after reading const tables"
    }
  }
}