SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '9db8b83b723df69ea7421597ae5556954feb1dcd7799131fa4c8f22683528026' 
  AND token = 'z4jLihkCKsOSxsFRJcdxlJzOPwwL7PbV9NDLAU9VeNI=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00030

JSON explain

{
  "query_block": {
    "select_id": 1,
    "message": "no matching row in const table"
  }
}