SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '2859038113a63e0f5c39ff6535a5147ff2d906bf7209ee546a9fa8c6239c8648' 
  AND token = 'kWIxnguRgpg2mOriBEuI44Cywz7GghyJdtijqET73Ic=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00044

JSON explain

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