SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '30b16c1d1649b8ec4bb7b264c76ed927791d9364dd7122d66bfdfea9a1b4c6ef' 
  AND token = 'JGytxxEJeEvCYZT6G0ZxmfkoKCwyZHCYuWhM/wPeLLc=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00025

JSON explain

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