SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'eaaf00ddc4c7bb8382041fd93fb40fd432703b5e9b0dbab36863bb06d8c6c318' 
  AND token = 'fBvEiZlqUtPITDVBWXWkU/ZQOWSJYBf2854vGBpioRI=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00017

JSON explain

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