SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '18d87597bc1fe7e98ff213b3a68da4d58981ac341d7dc02182b10867b0ff1336' 
  AND token = 'HOYux2wHBMEg74WSUebs+2j5sqIbmBuOadghm/RL/Jc=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00047

JSON explain

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