SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '88ccb72b6d13b0b725f3a246bcead1c195dd31d239ae0a7894f8542c4b918443' 
  AND token = 'XhIiSllbTRBNBn7NuXrkZshPezR0vpkD565SjlmNQL0=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00048

JSON explain

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