SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'f64f69b29c81a9e0e0dd7a323a83314655709cc47f4bbd349707e8c10600aad7' 
  AND token = 'NOJffSUsbjJsqvMiOdPLeAc1JOXTRMoB+qauJrvfsuQ=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00032

JSON explain

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