SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'a2c82a62e9d12d2281a03a4db2088d6efd5031b04e05cc9f704c447d5c903ab3' 
  AND token = 'QBNwijkUcrmPeC/hSSXDPrxFLZSKzWhRYSIcvog5H1w=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00037

JSON explain

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