SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'fa0da937d9c59ff3c5cfde45b382e6231ae4b485fbc086715a64477074002470' 
  AND token = 'L1FskyesBVAhUDRuktgbNARfbaMBIE9CokZPd/xiCD8=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00014

JSON explain

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