SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '77ad167712ca239a38473fa242f7c142d07fc23c7271f5c107233a771b238e93' 
  AND token = 'C7zlFSKX/SrSvsMIVgvYUMsEpsvGN2UWeECrF/skT2o=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00018

JSON explain

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