SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '4497798ba6c692833cbade42904f44c0ca42885d0e46bc321caa1e98a3feba60' 
  AND token = 'RosYZvDpAI2rK6s37krhXmBw2wpIbvix8Jl4Fnf2S58=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00025

JSON explain

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