SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '5f6a23ee2ffe6a5479808a45488b0f352d9070f8bd658dc93f6fcc0e71901b18' 
  AND token = 'mBL1SqtVFgt+0Te680ls3CTlwJzZpJeSh44/yY6vn48=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00025

JSON explain

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