SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '969e371adcef7344182722b38ff260a65194ec2ba8025f613f3f81dd2e582569' 
  AND token = 'mK0mRdJwMRh7qo39aPK6XOyvhrBsKpJZJY6IVR4bviw=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00020

JSON explain

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