SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '8c33e799edc54ca32cf73c158fd3ffb3442d751b797304dd8615865f47273ba1' 
  AND token = 'efTPSddhU6sstCaiLH6mz3gQCDk3DgnNi3EO4ay4KiU=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00019

JSON explain

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