SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '4e4399d0fc8ab65bc3520785912fbfcefb89b1f37b5ab7825c2af968d2708aee' 
  AND token = 'baPJJMOOTDpGHjG5M0+zo6vF2syISCx6Ds8/+v2Pa3Q=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00027

JSON explain

{
  "query_block": {
    "select_id": 1,
    "table": {
      "message": "Impossible WHERE noticed after reading const tables"
    }
  }
}