Sandbox

SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '0000311d08808ed6ded52d3d99b50890cee2f420c1f2a6b3ec25b15c2118c4a9' 
  AND token = 'm9ukUhIsVYCzQlKWToY/OZ3KjrpFSqj30ZcPwF3k9oA=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00021

JSON explain

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