SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '596e68afb56785b797b066500404799950367146c21735d81c5e7adefbb37821' 
  AND token = 'd+A7anG/4SI0VWcRIIsI7iXRCCHlDrnZFe2EfkmIdpU=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00033

JSON explain

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