SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '539b952e6a696639dd7a9bff632217b5ad79d3250ce8230a4c8ad5859d732b68' 
  AND token = '5WXMHBBsvqX7SuK/f4tzWvBwG4sOABmChbcVeZfnbu8=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00025

JSON explain

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