SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'ba6c8e88314b68457c0ef1018c10076db9a11283058d4cd98108c13e84a99037' 
  AND token = 'OieSfzuo0w716N4J5NHaS/0hI2j7z0RfHmT4lo3RpAU=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00017

JSON explain

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