SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'e10e942f9bfc44820ca0b4feeae1dc40867e80dc8faf7cd250a20831270ed561' 
  AND token = 'WuVWYjqVREbP9eRc0r6Esw5YO+3UGqSRFU9fRaP+DjA=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00043

JSON explain

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