SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'c44c5494f9d80967396eeb8f26eff23b9d611778e5c98cb2b9db036486031d74' 
  AND token = 'JVIRZGHUu1NSEaZsAJ04S/YGZFuXy2kQt+zxgl6L7EI=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00026

JSON explain

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