SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'e87efa27ea4cbda7432b6f65a08b1a7c87884ec99c3ee218892b769fc10e3367' 
  AND token = '/pKPorQJqs38HcBN4heaZGf+Cg1DsfNuTYwrOukWaRM=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00021

JSON explain

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