SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '422a4a375906aeaeba78f50de90051f9bcf3ed721e833efd68d9bdb22fa4e2ab' 
  AND token = 'Fy1pgnh8A1e5v2C7mhFkD7+tNCE4wx+HJAYN0VAArFs=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00032

JSON explain

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