SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'e86aacd08c2fd37776890f47ab515843a8913b453657ef87e47d30b41d7e8cf9' 
  AND token = 'hlQwXIYm5EP+i6uX+CAlH8cqQRyRGNzC/OYPtmjK/bs=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00038

JSON explain

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