SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '7e306602e334b698addc05cd440ea8c03416ca266ac2c12b89bdb1b79592fc84' 
  AND token = '5EU7LI8Cq5GU6Vfa5xWqV0MUbFJaupl2VoiwjVso6Xs=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00029

JSON explain

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