SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '7b16936f3e209eb167f8c6db1a5cbf7de82ebc3903d4c4e92efcabd646badf54' 
  AND token = 'lZ2w8H4HSuZEHOXSjae5trJxslUtuKBNB8sGiCEczIM=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00022

JSON explain

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