SELECT 
  1 
FROM 
  cscart_june_setuplock_keys 
WHERE 
  key_id = '5817333a57525abbb405768caa50f3c9db5689d87898295c38b0cdbb23d96e7a' 
  AND token = 'u3DAEPV+07jMwdCGePtO3LcsFu3RsQ+WBRx+l5l6DbA=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00028

JSON explain

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