SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '9aba6fd314965f33412842ded71b5b392fe24974082e90e641bc81e7f1d2845b' 
  AND token = '1xDFwFh/uy6qAylrdffn/mMu4YIGpOFByAuLFQhfAfY=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00041

JSON explain

{
  "query_block": {
    "select_id": 1,
    "table": {
      "message": "Impossible WHERE noticed after reading const tables"
    }
  }
}