SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '874251d757b3e75bdf496b318d783664622070327cbcf17bd016bb82a80d77a0' 
  AND token = 'K+yfdhh3OfQY/2YnxXCLvFvAbzGDOK9oAICEIPGgf30=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00043

JSON explain

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