SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '4cb9a9e4ae8df81080703d23a8508eade12f377e5910107f80437797fa8478bd' 
  AND token = 'O44/0aTsrxc93YhXMzkVZROyJ0oSfKgXVPJIo13iSgE=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00013

JSON explain

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