SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '6083395e2be528950d11a3493e126d8d227fbcc011529d1f8232ba7363cebdfa' 
  AND token = 'kc1WK3zrlqIokL1OMo3PFO23nhtn/QDlvNQFJJ2kmFU=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00028

JSON explain

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