SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '651674ddbd04684b0711c24e2759ba6c8c6f2ca90f19ba5d17aba4f5723a7278' 
  AND token = 'HtM8NiFsb4Hg9828Hu4+EKGmxFDKMX8+HAa+NPYFNeU=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00018

JSON explain

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