SELECT 
  1 
FROM 
  cscart_aprillock_keys 
WHERE 
  key_id = 'e42eafff12d237742c44fa596a007a8b9b46873730f9de258c6d15b99c85f623' 
  AND token = 'vRSvu25P+bXoJIiAZ3mhVexoF6zcsOQXNBhQ8eD7SFs=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00019

JSON explain

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