SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '3f224f4d5bc491b8a6cd4e09a074b8221165eb75c5a8507e6e3a92afeabc36a0' 
  AND token = 'gDOg/mkasLezPM2OuZRlWzGMTw+q+lqMj8sfJPHlUbM=' 
  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"
    }
  }
}