SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'd867af49c49883d1c4dc6a97afb42a18d129f8e9a82feeb394aabe1ccfac48e0' 
  AND token = 'CGu2sZOztMw0cEzJwMV60wC+TpGn/gqZ4nHHFjBhSIo=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00031

JSON explain

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