SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'fa0e3936fdd2c8b7ae6699449009498457676fd244cecaa7aafe376f29fc12a4' 
  AND token = 'ZN+kKfYjqu8XvITjlFxhSXKL0tEA5DDAJpGwND+o40I=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00035

JSON explain

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