SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '1bd67481c863a146ccce3116fb8ba39c9ef1968934b9251d57d51d5bccd8e6e8' 
  AND token = 'hWu7+YK3QxgwuXJIzOzY69Z4myhrxSmIB4k+zkR0Urs=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00047

JSON explain

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