SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '96c78fadda7e7362e414235a880307a8691a40bc9e6ebaf4bcf893e5851c57b4' 
  AND token = 'MGHivzAVCsCrep6cq+VUEpS1LzQwrDk2rk9iicXOdvY=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00032

JSON explain

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