SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '79114d835192fa4eb8efad4a86a518e7d609fbfd90a329a51247eb23efadd134' 
  AND token = 'S2zE//NdE8W9KIDQD0FI+4EPqDCd3OWAuRlKzTeTvaM=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00039

JSON explain

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