SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '79a1ab2f2bfe14da9f2f132c4013879a1deb703364f51375b5246b55ff5e3d30' 
  AND token = '04tuYdB/bbOVGpRP+WoenunW3HK87w9K97zqJ7peXmY=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00025

JSON explain

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