SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'fa50a0d05b4177747b789ac5d9727a9d0973acd3b788005bd867e23cf9c2431e' 
  AND token = 'zPUN1BwYDfjYzZouwoK5Ab+kqcrg1ZBkmjG5u3gskJo=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00024

JSON explain

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