SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '34d05ea89bf9a27f65628b61832cb13cc61f4f6435232c8debafbdc79ed93a5c' 
  AND token = 'zVMAaSzZGmrRuHD2lFfX/rtbsPfN/4QfDbOpN+zSxQg=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00036

JSON explain

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