SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '6be8983c51223dbc8abeccc4ada56525cf14a6e3d50d1649caff3501d2fde50b' 
  AND token = 'KTFT6zKahKdwm62Y/3tIXSjtJ9KioVk9IkEVBLhKDow=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00030

JSON explain

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