SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '9fe2e8ccd643107d0d00bb28970e961f273d231206c5346c6fe151a72d9e10ea' 
  AND token = 'iqmyVAvxt2Akt92srcZIBbkkYyLWn/QBsws3mQme1Pc=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00070

JSON explain

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