SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'f7ae897575189873a90f3e65a789f64996cee720f0e87255884fa66355885310' 
  AND token = 'uD+s0KZIhlYY6GOSXT5GwcHxsBUNvDVOfB6bpAluQAI=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00035

JSON explain

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