SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'bf93ec4df81db0427854a9cc36c01e0c106279f1e994bcc858ca77c5ff9fa71e' 
  AND token = '6q5sCYP0WsBdyBnypV9JlcgVz9+Z+Li+ZSUvQpD5i+M=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00024

JSON explain

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