SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '9bd46296ef125753854c407775cd3788eea357360a7b06196f5d359837d51ad1' 
  AND token = 'L/E9VwkjQUL2VOLsvo5Wfq/rBzlV0FWQ+Qgh80gQFxQ=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00022

JSON explain

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