SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '9ac159632488f85e0259e65dc7d7e74518e9621247715f5457c554e99bd4a50a' 
  AND token = 'ERKnvYjzizZrIgN2BjW6senEFTDSxnVCjM3RuKOIORk=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00023

JSON explain

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