SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'db3e23fd7e580ecd6aa682df461dc4bd2f58058e3257e1c143a6c9323f0a465f' 
  AND token = 'aAGTnoUQBn5ifI05rRI+9HadtdTpEsxLAX+GA6N50CQ=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00022

JSON explain

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