SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'b1e620caf32d1731fd0e4b036094b01ba6a89ccceadb6b67be981eaef1783c62' 
  AND token = '/NKsHaBNqeXoIJEmK7Um7SFgYrTD9BTJgin3pPQfkoU=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00024

JSON explain

{
  "query_block": {
    "select_id": 1,
    "table": {
      "message": "Impossible WHERE noticed after reading const tables"
    }
  }
}