SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '8142355c6c84ad2b730834657deb40c15dd45015e2f167e0aa3d7d5690fdc001' 
  AND token = 'ezqBH+FmliJTZcBCTLpnYwxuuxMxB8gV89ggjJ1sMkk=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00035

JSON explain

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