SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'd92ad385466dd46f28c9523a286d2a3559a2ce8798b2d5d276b29e6ddf7a3a60' 
  AND token = 'fuLygwxt3CiNc4TZafntnzMBBKKq68+NOKWzds9VJSs=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00038

JSON explain

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