SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'fabedf6824ceb231a5730028364037b5c868636c0581fa784cae4aa0b02ba7e1' 
  AND token = 'BE4KP41GLDbC41NTEC+PsHaqpl1VfaaGN2D+mYn+8/o=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00022

JSON explain

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