SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '7e79722c8c62b7470561d1b940c45d13f86aea003abad3b882138c0f6ea7e711' 
  AND token = 'LCUsmLZMtNLIb5wjLDDQLsOhzMjkqwgMc9H8r8Yd6OE=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00023

JSON explain

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