SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '3f1407768f327cf6fb1b57f66c21d0db4cace37a3aef0fd4289411e45cb50bcf' 
  AND token = 'VuVU3oAzncYHVAYSvLBeB6WCTxxDisE4KS5Rum05zE4=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00033

JSON explain

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