SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'bfc625eed8f4b614cb83f5135e8ae8ead1e0dd839b302fdbe82d18de99402aee' 
  AND token = 'fTVaX4z6mDpvny/VEwO+QanQQM1LmiXe+Lq2huv1hVI=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00021

JSON explain

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