SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '7522dc78568050ec8301f85113b848431908038930cdf1f8c36a3f2351607941' 
  AND token = 'at5ZjfyGCKczUBATYVUlp7v3gRZV0l0QIUZQJCvIYnM=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00031

JSON explain

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