SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '7f1dbd3b24497cc2bfb2768f608f41e3db96726fed6ce4e384e3e94e6dad16b7' 
  AND token = '/AsKXy5Vo6pEmVDFKIBpDSV+vnrPlgiPYbPpy2Zz0F0=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00028

JSON explain

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