SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'd88218611492c89b5533079caf90e142e7d478d62dac1583f971e4b4026320a5' 
  AND token = 'tiadaWai7ebttHLUWO0gta/FRvarlDMSgnkFhpyCfVM=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00020

JSON explain

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