SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '4531cbc663d608edbc6c762dc2696368b5ae5970c13ad867cbb85b72f6f72261' 
  AND token = 'M1Yrx8eSddijcIXkwe8XkraQD326Bs3gyVEyDOmEynE=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00017

JSON explain

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