SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '2216a762c8495217d5ce341c8dcfef638f607da5c924378699fecafce00c0fe9' 
  AND token = 'dASL+x8uSJa7gmFAe5yYRC8XzEXcYjLtt2lxCQjzImE=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00032

JSON explain

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