SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'ed1afc4d5f3230add3651f1c480d9f2bbb8ad5478423ba382dde7a026b4d8d5f' 
  AND token = 'DUbW5fYZtFcNvjz+JPsBxevLge2dK9cNtxFPEzkPs4I=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00027

JSON explain

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