SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'f49a25266782fcd454b7110d496702044ae10cd5abc6683a35317fb1bcb9d8c7' 
  AND token = 'uiauGBAXEkJJJKEGKYEVZROg4N1gI0fpOMctMiuSMnc=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00025

JSON explain

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