SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '1caf6f7d49453b12a51d11fe8437a0ab5d17f51c958d64c00184c4a2fb50faa5' 
  AND token = 'wgGp/ULgtf4gvlOoOjgLHLB6nSJNu/WJ9mkMfuxvYrI=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00032

JSON explain

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