SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'fe28a99ce805cf7d711827448db860ea7eb419ba09fc8caeb5e1397c9266144f' 
  AND token = '8S9VQbX1XG52sOkQpU4JuKRcDORdJJ+r0TDaM9YY+tE=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00028

JSON explain

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