SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '66474543463aeb8288e7553a73e74954cacb2ae81a494a455a901ae430b8a105' 
  AND token = 'Z5coRLuMtOYoLvK+1fi9u27UuL8ymgcRe9b7IwAF6YM=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00030

JSON explain

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