SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '74f612876008023865f53c574c3f0ba594b5b35bd95d0724ea7946776ab591ea' 
  AND token = 'skCHsX16lQYFmnDNtcdjIDOOJ3lIxnxWRIJQ0PCj+Is=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00044

JSON explain

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