SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '764c8134536c57b3c9dbb01d4f96f810007026a282f524976011be4714c0cf6d' 
  AND token = 'qnGqJLz7nBRjSDOaBxnFk+pbDfbWY83mluMFE9XKSdY=' 
  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"
    }
  }
}