SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'b5c1ecd15607d8ca3802e8a05d31865ec4749c6632234f26d25a51973d558e7b' 
  AND token = 'RD5Hn2hVfpttWgvh9YcdvFP1iMCKONbFCCSU2cRrva4=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00022

JSON explain

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