SELECT 
  1 
FROM 
  cscart_june_setuplock_keys 
WHERE 
  key_id = '54b613765597b43a5439ce8249584c3e7860e1b0bd8bb2018f6f8e2876e62f73' 
  AND token = 'GP9+VKzw8pOQCthxxYqj9mFUluim6yjm//4QmAqDDiQ=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00029

JSON explain

{
  "query_block": {
    "select_id": 1,
    "message": "no matching row in const table"
  }
}