SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '3ab72c41694d65f5193bac81bedab84d574475086f7447ab3b2253e562826b73' 
  AND token = 'fYdd3a8mZ2uMkQNIgTCiizN/YHUyWsSri8BFz7mPDaA=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00053

JSON explain

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