SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '4cca33f1151ec1673764defe1e3b58512842c552cbfd79dbace032860748f219' 
  AND token = 'k/bgEugAOuY1Bf3yOHQZmUsOdCBxfBDzq49vfre1S+w=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00019

JSON explain

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