SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'fc67e63162b072731dd90c18b445ff557c6386f913561e3cc2a68fb031fe9861' 
  AND token = 'Mcof3ku0972txM4kaaNQ6HVgDYTZ1n/w5hUh+NUuJcM=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00027

JSON explain

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