SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '5bfdeada2046ad64a1b14469346733bd3fe3d156e1e53a0cb872c9830d29519d' 
  AND token = 'bu6gTwQ4Dijwq2ubYswWw/7Qpx45UudlrPLXBmB/xzA=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00019

JSON explain

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