SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '2e8386f824fb01cce9e70065d22df3a33de22b1d0605c3750f505b894309c2f0' 
  AND token = 'bmjYwAZ31qBc6NqkUbxtrMeOzkvKUHeZTTaAPwhiVgQ=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00017

JSON explain

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