SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '0369ee20df3ed32eb54a7395a1c6dfa79dc80d344611019637f0d317c1f538bc' 
  AND token = 'sGIZ2vnZ8YwnEG/0fisvLnaS/ConBJ4PULB+tgJrGN8=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00028

JSON explain

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